Telegraphic receiving and recording apparatus

ABSTRACT

1,102,690. Electric selective signalling. SCM CORPORATION. 23 Nov., 1965 [23 Nov., 1964], No. 49790/65. Heading G4H. [Also in Division H4] In a mosaic printing system as described in Specification 1,069,521 (see Heading G4H) the Start bits are transmitted as a frequency distinct from any other part of the character-representing signal. The receiver operates in response to this frequency provided that a preset number of Start bits is received.

June 4, 1968 Filed Nov. 23, 1964 E. E. KLEINSCHMIDT TELEGRAPHIC RECEIVING AND RECORDING APPARATUS 4 Sheets-Sheet 1 68 GENERAT 5 20v 0) moo] .D. XMTR I; 7

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BY f/M,

ATTORNEY 5 June 4, 1968 E. KLEINSCHMIDT 3,387,037

TELEGRAPHIC RECEIVING AND RECORDING APPARATUS 4 Sheets-Sheet :5

Filed NOV. 23, 1964 INVENTOR @WAED E ALE/NfiCHM/OT BY M YZQQM ATTORNEYS June 4, 1968 E. E. KLEINSCHMIDT 3,387,087

TELEGRAPHIC RECEIVING AND RECORDING APPARATUS Filed NOV. 23, 1964 4 Sheets-Sheet 3 (To 37) (T069) ---r INVENTOR.

ATTORNEYS June 4, 1968 E. E. KLEINSCHMIDT 3, 0

TELEGRAPHIC RECEIVING AND RECORDING APPARATUS Filed Nov. 23, 1964 4 Sheets-Sheet 4 COMMUTATOR L|Z34567 09 Ill INVENTOR' fDWARD E KLE/NscHMmr BY ,QMVZM M esuumc 12 5,

ATTORNEYS United States Patent 3,387,087 TELEGRAPHIC RECEIVING AND RECORDING APPARATUS Edward E. Kleinschmidt, Miami Beach, Fla., assignor to SCM Corporation, New York, N.Y., a corporation of New York Filed Nov. 23, 1964, Ser. No. 413,162 12 Claims. (Cl. 178-439) ABSTRACT OF THE DISCLOSURE A reproducing receiver having a printing mechanism to progressively inscribe a symbol by a group of intrasignal pulse unit current conditions in a symbol signal having a point printing operation magnet for receiving and accomplishing printing of the symbol portions of said signals by cooperation with a line platen. The receiver has a cycling start-stop device including a start-stop magnet for starting and stopping the printing mechanism once for each complete inscribed symbol. A special circuit starts the start-stop device upon reception and detection of a signal in which at least one initial pulse unit has a frequency higher than the frequency of the following intrasignal pulse units to enable starting the operation of said point printing operating magnet during and responsive to the subsequent intra-signal pulse units of said signal. The stop operation of the start-stop device occurs subsequent to a predetermined operating period of the driven printing mechanism and places starting control for the receiver back under command of the special frequency detecting Background of the invention This invention relates to a novel control circuit for a start-stop type of telegraphic system with receiving printer unit, such as a telegraphic progressive printing system, having particular utility when transmission is via channels which also carry voice communication, e.g., telephoneand radio communication channels. More particularly, the invention pertains to the utilization of a unique signal, such as a high frequency tone signal in the audio frequency range and above normal voice frequencies, as the start signal for signal impulse combinations utilized in transmitting direct representations of symbols by multiple pulse signal groups.

The telegraphic progressive printing system circuit shown in application 'Ser. No. 278,241, filed May 6, 1963, now Patent No. 3,324,240, patented June 6, 1967 by E. E. Kleinschmidt et al., utilizes a conventional telegraphic channel connection between transmitter and receiver. When transmission is accomplished through radio wave communication channels, particularly at frequencies in the voice frequency range, the necessities for a stop signal potential being constantly applied to the communication channel during all stop" periods may result in a continuous tone being transmitted during such periods. The tone would be objectionable if the same communication channel is also being used for voice communication. Besides, the fact that the stop signal potential can be a source of frequency tone irritation on the voice channel, static interruptions could disrupt the start and stop periods of basic message units, causing inadvertent starts and disrupted or confused symbols recordation.

Accordingly, a primary object of this invention resides in the provision of novel apparatus for use in the combination of a message communication system, wherein the same communication channel is used both for voice communication and for signal transmission via a start-stop telegraphic code signal transmitter and receiver-printer, the novel apparatus enabling minimum interference with 3,387,087 Patented June 4, 1968 "ice voice communication by use of a unique message code unit start signal having a frequency which is different from normal voice frequencies and the intra code signal pulse frequency.

A further object of this invention resides in the provision of a novel, simple radio control circuit to enable satisfactory start-stop control, yet eliminate undesired tones and inadvertent starts of receiving equipment in a telegraphic progressive printing system when radio wave communication channels are being used for transmission. This circuit may also be utilized in combination with the telegraphic progressive printing system when other transmission channels, such as telephone lines, are used to connect transmitter and receiver devices.

Another object resides in the provision of a novel data communications system which includes a printing receiver for receiving signals, each of which signals includes unique start pulses and a plurality of pulse units representative of a specific symbol, and recording those symbols by making a printed record on a record medium such as a page of paper, and a novel transmitting mechanism including a diode matrix system and a communicator device for originating and transmitting each signal with its unique start pulses and plurality of pulse units in a predetermined order representing the symbol being transmitted, the unique start pulses having a frequency different from the intra-signal pulse unit frequency, and the receiver including a device for detecting and utilizing the unique start signal to initiate a receiver operational cycle.

Still another object resides in the provision of a data communication receiver-printer for receiving and utilizing coded electrical signals, each of which is a single signal message unit consisting of a multiplicity of intra-signal pulse units starting with pulses having a frequency unique from the intra-signal frequency of the pulse units, the receiver printer including novel mechanism for recording by progressive transcription printing the symbol represented by a received signal and including a device for detecting and utilizing the initial unique pulses of the symbol signal to start printer recording and electro-mechanical mechanism for automatically stopping printing recording after each symbol recordation.

A still further object resides in the provision, in the receiver portion of the system included in the preceding objects, of novel printer recorder cycling control mechanism which includes a power operated mechanically rotatable stop member, an electromagnetic start-stop device having a spring biased armature, shiftable, upon energization of the electromagnetic device, to blocking disposition in the path of rotation of said stop member and shiftable under its spring bias in a direction to remove it from blocking disposition, and apparatus including an electrical energizing circuit connecting to the electromagnetic start-stop device, rendered operable at the end of a printer cycle of symbol recording operation to move the armature into stop position and to energize the electromagnetic device to maintain its armature in stop position, the electrical circuit including a normally closed circuit control switch connected to and operable by a portion of the receiver capable of detecting the unique start pulses of each signal and responsive to a predetermined succes-. sion of the unique pulses for de-energizing said electromagnetic device and thereby initiating a printer recording cycle.

Further objects of this invention will become apparent from the following detailed description and the claims when read in conjunction with the accompanying drawings, in which:

FIGURE 1 is a diagrammatic view of the transmitter unit which employs the present invention, showing, in elevation, a single key and switch assembly and also broadly illustrates the concept by which the key controlled switching system connects to set up a matrix group which in turn connects an electrical signal source to selected segments of the commutator and thence to the radio transmitter;

FIGURE 2 is a schematic wiring diagram for the receiver-printer employing the present invention and includes radio receiver circuit connections to the tone detector start control circuit, the start relay, start magnet and print magnet;

FIGURE 3 is a perspective drawing of a telegraphic progressive receiving-recording unit capable of being utilized in combination with the circuit of the present invention, the cover being removed to illustrate the working mechanism and location of major components;

FIGURE 4 is a reduced size perspective view of a complete keyboard transmitting unit which can be utilized in conjunction with the present invention;

FIGURE 5 is a reduced size, perspective view of the receiving printer unit shown in FIGURE 3, in this instance, the cover being in place;

FIGURE 6 illustrates details of components located on the right-hand side of the receiver wiring diagram of FIGURE 2 and shows the start-stop mechanism with the start magnet switch open, the carriage return-line feed switch open, the print switch closed and associated mechanism in an operative, i.e., cycling condition;

FIGURE 7 is similar to FIGURE 6 and shows print switch open, the start-stop magnet switch closed, the startstop magnet energized, just prior the termination of the operative cycle, and the carriage return-line feed switch closed;

FIGURE 8 is a view similar to FIGURE 7 with the start-stop switch closed, the start-stop magnet energized and holding the cycle stop lever in stop position and the carriage return-line feed switch open;

FIGURE 9 is a schematic layout illustrating an exemplary 48 segment transmitter commutator, a portion of an exemplary keyboard controlled diode matrix group with connections to the commutator segments and several of the keyboard switches; and

FIGURE 10 is a block representation of the letters E and K which is characteristic of the type of printing provided by the progressive printing system, the shaded squares being the units of the block in which printing must be effected to accomplish progressive formation of the letter, the shaded squares being numbered in the order of their progressive recordation on the paper.

General Operation The invention will be described in conjunction with its use in a telegraphic progressive printing system (see FIGURES 3-4) which includes a transmitter unit 39 (FIGURE 4), a receiver-printer unit 32 (FIGURES 3 and 5) and an interconnecting communication channel. Each unit is connected to a local power source (not shown) furnishing electrical power, e.g., 110 volts A.C. for drive power and appropriate DC. voltage for signal and control circuit power. The output signal line from the transmitter unit can be connected by direct line, e.g., a power line circuit or telephone line to the input of the receiver unit or transmission may be by means of radio equipment through a radio channel such as diagrammatically illustrated in FIGURES 1 and 2.

The circuit arrangement for the system as disclosed and described in application Ser. No. 278,241, filed May 6, 1963, by E. E. Kleinschmidt et al., illustrates use of a direct line telegraph circuit where a normal DC. voltage is impressed on the line circuit and the receiver-recorder cycling operation is started by the interruption or polarity change of the line current.

When operating the system over a radio frequency communication circuit or over a voice frequency circuit as permitted in two-way mobile radio system, cg, police cars, the record cycle start operation for each unit in a message is preferably accomplished in a manner difierent from that used with a direct telegraph line. Apparatus to accommodate and enable the different manner of starting each recorder cycle is shown in FIGURES 1 and 2 and is described generally as follows.

The radio receiving apparatus will include equipment to detect and utilize a high frequency in the audio range as a start unit in a pulse signal combination, convenient suitable frequencies being in the vicinity of 1000 to 1200 cycles to thus be above both the intra-signal pulse frequency of the message units and the frequency of normal speech and distinguishable from noise due to radio interference such as static. When the unique signal pulses of such high frequency are received over the communication carrier, they are utilized to operate a device which controls a receiver circuit including the printer start electromagnet 37. De-energization of electro-magnet 37 is used to start a recorder cycle of operation.

' FIGURE 2 shows the receiver-recorder start magnet armature 72 just after it has been moved by a cam to close a start-stop magnet switch as the end of a recording cycle of operation approaches. This action closes the above described receiver circuit including the coil of the start magnet, normally closed contacts of a high frequency controlled relay and the local power supply, and energizes the start-stop magnet which maintains its armature in stop position prior to completion of a recording cycle of printer operation. I

The transmitter and receiver units per se are described inthe aforedescribed application Ser. No. 278,241 but they are also herein described to an extent enabling an understanding of an exemplary system and the nature and utilization of the present invention.

The power supply circuits to the transmitter unit 30 and the receiver-recorder unit 32 (FIGURES 3-5) are turned on by respective ON-OFF switches 33 and 34 and, with the radio transmission and receiving equipment operative, the message data system will be ready for operation.

When receiver-recorder control switch 34 is turned on, motor 36 (see FIGURE 3) is energized as is also the start-stop magnet 37 and the latter immediately blocks all recorder functioning activities of the receiver-recorder until the first incoming pulses (unique start pulses) of a transmitted message unit signal are received from the transmitter 30 as will be explained in greater detail hereinafter.

Transmitter A group of timed sequential pulses of a block grid signal combination will be generated when a key 38 on the transmitter unit keyboard 39 is depressed. Referring to FIGURE 1, when key unit 38 is depressed it is moved down against the biasing force of a spring 43 and thereby moves a lower key lever 42 in a CCW direction. When released, the key unit 38 returns under spring bias to its normal position.

Upon depression of a key, a projected lever arm 46 on the lower lever 42 pushes up against one arm of and pivots an associated switch operator lever 47. A second arm 48 of the switch operator lever 47 will engage and cause two associated leaf switches 49 and 50 to close in rapid sequential order. The first (upper) switch 49, when closed, connects a circuit to a diode matrix bank 51 (see FIGURE 9), setting up predetermined circuit paths through selected diodes in accord with the key which was depressed, and then closure of the second switch 50 completes a circuit to the keyboard transmitter starting mechanism.

The diode matrix bank 51 in the keyboard transmitter unit may be wired to form various characters and symhols, so long as such symbols can be formed within established limits of the grid squares in a symbol block, such as shown in FIGURE 10. If desired, these limits can, of

course, be expanded as contemplated in application Ser. No. 278,241.

The various symbol keys on the keyboard are similar in construction to the one illustrated and described with reference to FIGURE 1, and each key will operate two associated leaf switch contact units, the first unit of which in each case connects a circuit to a desired specific matrix diode pattern associated with the character represented by the specific key and the second switch unit of which energizes the transmitter start magnet. In addition to the keyboard 39, the transmitter unit 30 incorporates a motor driven commutator 52, by which the key selected matrix diode circuits are completed and energized in a predetermined order and timed relationship, and an electromagnetic commutator start-stop mechanism 56 and 57.

The transmitter commutator 52 is diagrammatically shown in FIGURE 1 (it is also represented in FIGURE 9) and, in the exemplary embodiment herein described, consists of forty-eight individual stationary segments 53 arranged in a ring. The segments used for symbol forma- .tion 'have no electrical connection with each other, although other segments used for some functions are bridged. If more complex characters or additional recorder functions are needed, or if more time is necessary to accomplish the existing functions, additional segments 53 may be added to the commutator. Thirty-five of the first thirty-nine segments 53 of the commuator 52 are directly connected via individual lines 54 to the diode matrix bank 51 (only one line 54 being depicted in FIG- URE l). The connections will be expanded in more detail hereinafter with reference to FIGURE 9.

After the first switch 49 (the matrix switch) associated with a depressed key is closed and has selected the desired diode pattern in the matrix bank 51, the second switch 50 is closed and completes a circuit sending current through a one-shot multivibrator 55 (FIGURE 1) which momentarily pulses the keyboard transmitter starting magnet 56. When energized, magnet 56 attracts its armature 57, shown in FIGURE 1, moving it so its blocking end 58 shifts away from the path of a commutator shaft blocking arm 59. This permits the blocking arm 59 and commutator shaft 60 to start rotating due to motor drive force transmitted through a slip clutch (not shown).

Attached to one end of and rotating with the commutator shaft 60 is a wiper arm 64 which in turn is fixed to a wiper disc 66 also rotating with shaft 60. Working in sliding contact relationship with the rotational wiper disc 66 is a brush contact 67 (FIGURE 1). It is through brush contact 67 that electrical pulses, sequentially derived through contact by brush 64 with selectively energized ones of segments 53, are sent over an outlet line to the radio transmitter 68.

A continuously running, fixed frequency oscillator 61, e.g., having an output of 1000 cycles per second, can be connected to the first several commutator segments #42 and #43 (see FIGURE to impress a 1000 cycle signal of fixed duration on the start segments or, alternately, as shown in FIGURE 1, a 1000 cycle per second oscillator 62 can be triggered to on by a parallel commutator device 63 only during passage of the wiper over the first several commutator segment positions labelled X. The amplified message unit signal consists of the group of high frequency star-t pulses and the remainder of the block grid pulses generated during a cycling of the commutator, all of which are sent out in sequence over the radio network to the receiver-recorder circuit (FIGURE 2). The

' first sequence of pulses, i.e., those of predetermined frequency, are used for triggering the receiver-recorder start magnet 37 and the succeeding pulses of a signal are directed through a receiver-recorder circuit including the coil of the recorders print hammer operating magnet 69 after certain switching operations have been performed by the triggering of the start magnet mechanism, as will be explained hereinafter. Note, the rotational speed of the transmitter commutator segment wiper 64 is such that it will make :a complete rotation before the key operated matrix switch 49 can open due to the operators releasing of the depressed key. Any depressed key must be released in order to reset the one-shot multivibrator 55 and transmit the next signal.

The basic signal for the system message unit is derived from a character or symbol block made up of forty-eight individual and sequential pulse units which, for convenience, can be referred to as either mar or space pulse units. Each pulse unit of a message unit signal corresponds to a segment 53 of the commutator 52. In FIGURE 10, the signal pulse units are represented in an arrangement of six vertical rows of eight pulse positions or squares in a rectangular block. Thirty-five squares (or pulse units) of the signal block are used to form 'an actual character or symbol (including blank and space) while the remaining thirteen squares are used in the per formance of or to effect the various functions such as character spacing, line feed, carriage return, stop and start. This is more clearly illustrated in FIGURE 9, where each numbered commutator segment corresponds to the same number in the squares of the character or symbol block (FIGURE 10).

As stated hereinbefore, the diodes in the matrix bank 51 are wired to set up circuits tothe appropriate commutator segments for desired characters and symbols in accord with a depressed key and each of these characters will be printed on a page of paper 40 in one or more progressive printing sequence passing down from square .to square from the top to bottom of each vertical row starting in the first row in a character block progressing through the first five rows from left to right. This is more fully explained in the aforenoted application.

Receiver After the transmit starting magnet 56 (FIGURE 1) is energized to unblock the commutator shaft 60, the wiper arm 64 begins to move around the commutator 52. During initial movement, the wiper arm 64 moves off of the stop segment #41 (see FIGURE 9), which in accord with the present invention are dead contacts, and moves on to the start segments #42 and #43 which are impressed with or control generation of a 1000 cycle signal. Since the second Wiper 67 is in continuous electrical contact with wiper 64 and is connected to the transmitter output, the signal cycle will commence with two pulse units of 1000 cycle frequency. As has been described, if several more pulses of 1000 cycle frequency are desired, more segments can be used in the commutator.

The receiver-recorder 32 will be stopped at the end of a message unit operational cycle whenever the start magnet 37 is energized. The cycle is started by momentarily de-energizing the start magnet. As has been generally described hereinbefore, when the receiver power switch 34 is turned on, the start magnet 37 is immediately energized, attracting its armature which is the stop lever 72, and blocking rotation of the recorder vaned drum 86. The start magnet 37 is energized by a circuit from bus 278 connected to the negative or ground side of a local D.C. source of potential, through the coil of magnet 37 and line 272 to one contact 94 of a leaf switch which is machanically closed by the stop lever 72 when the vaned drum approaches a stop position. The circuit is completed from the other contact of switch 95, through a line 273' to the normallyclosed contacts of a special start relay 70 and thence to a bus 286 connected to the positive side of the local D.C. source.

Excepting -for the manner of and circuitry for energizing and de-energizing the start magnet 37, the cycle of re corder operation is the same as that described in application Ser. No. 278,241.

Referring to FIGURE 2 (also FIGURE 8), the receiver is in a stopped condition, with start-stop magnet 37 illustrated in its energized condition, which pulls and holds the stop lever 72 CCW with its blocking arm 75 positioned in the path of rotation of the carriage screw cam stop arm 76. This position of stop lever 72 and engagement with stop arm 76 stops the rotation of the drum and of the hammer carriage screw 92, thus preventing the receiver 32 from undergoing printing cycle operations. During periods when no symbol logic is being transmitted, this receiver stop condition will be maintained because the start magnet local control circuit enables current to be channeled through normally closed contacts 180 of the special start relay 70 and through the closed start magnet contacts 94 of a SPST switch 95 to energize the receiver start-stop magnet 37.

The start of transmission of the next character, as has been described hereinbefore, results in the transmitter wiper arm 64 moving onto the start segments #42 and #43 (FIGURE 9), thereby impressing a 1000 cycle signal on the transmission output. The 1000 cycle start tone may be transmitted on a specific radio carrier wave whe'eas the signal pulse units could be transmitted on the carrier or can be transmitted by keying the XMTR CW in any well-known manner.

The radio receiver unit 182, to which the receiver-recorder 32 is connected, has a signal receptor 183 for receiving the carrier frequency. A signal line 184 to the receiver-recorder 32 can be connected to the signal receptor output. In the radio receiver, the signal receptor output signals are demodulated and the 1000 cycle frequency pulses separated from the carrier and passed through an audio section 185 of the receiver to an earphone or speaker. As audio output will carry the 1000 frequency start signal a line 186 from the audio output connects to a 1000 cycle detector tank circuit 187 in the receiverrecorder, which in turn controls the bias voltage of a power transistor 188, the detector circuit being connected across the emitter and base terminals of the transistor. Under the condition of a 1000 cycle signal being applied to the detector 187, bias voltage generated through the detector tank circuit and applied to the base of the power transistor, causes the transistor to conduct between its emitter and collector, or in other words, to turn on.

Start relay 70, contacts 180 of which are normally closed, is energized when power transistor 188 turns on. The start relay 70 is a delay acting relay with its delay period chosen so that it will operate when subjected, for example, to a two pulse unit time period of Operating current from power transistor 188 which etfectively prevents random pulses of 1000 cycle from operating the start relay. The relay 70 may be designed to require more than two pulse units, e.g., three or four, if desired. If the received tone signal time period exceeds the built in delay time period, relay 70 will be momentarily operated, its normally closed contacts 180 will open and electrical power will be instantly removed from the holding circuit for receiver start-stop magnet 37. The receiver stop lever 72 (FIGURE 6) will immediately pivot CW on its pivot pin 73, under force of its bias spring 74, so that its blocking arm 75 i instantly moved away from the path of a stop cam 76 on the receiver function shaft. Relay '70 is de-energized as soon as the 1000 cycle signal is interrupted by virtue of the transmitter wiper 64 passing off of the start segments.

During this time, the receiver motor is continuously running and transmitting drive power to a large gear 82 (see FIGURE 3) which is part of a slip clutch 84. Thus, rotational power is transmitted to a vaned drum 86 which, like the driven components of slip clutch 84, is fixedly attached to and will rotate with the function shaft 87.

Another large gear 88 is secured on the opposite end of the receiver unit drum shaft 87, gear 88 being meshed with a small gear 90 in a 4:1 ratio. Gear 90 is non-rotatably fixed on a print hammer carriage screw 92 and imparts rotational movement thereto (see FIGURES 3 and 6 through 8) whenever the drum or function shaft 87 rotates. By appropriate timing of the transmitter commutator operation and the receiver drive motor and gearing, the time period needed for a complete signal cycle is made equal to a one-fourth revolution of the drum shaft 87. Therefore, when gear 88 makes a one-fourth revolution, the carriage screw gear 90 and of course the carriage screw 92 itself will make one complete revolution. The drum shaft 87, gear 88, gear 90 and carriage screw 92 will be automatically blocked at the end of a received signal cycle by the start-stop magnet stop lever 72 in a manner as will now be described.

During the receiver print operation cycle, when the stop lever 72 is released, as shown in FIGURE 6, and rotates CW, a control edge of an upper stop lever finger 77 moves away from abutment with a switch camming button 98 of SPST switch 96 permitting its movable contact arm 100 to spring in 2. CW direction, releasing SPST start magnet switch and opening its switch contacts 94 which holds the circuit to the start-stop magnet 37 open even though the special start magnet relay contacts 180 are now closed or in the process of closing because of termination of the 1000 cycle pulses. The same movable arm of the second SPST switch 96 simultaneously closes contacts 102 to connect amplified signal pulses, derived from the receiver circuit line 184 through an amplifier 190, to the print hammer magnet 69 (see contact position in FIG- URE 6).

Viewing FIGURE 1, the transmitter wiper arm 64, upon continuing its rotational cycle, moves on past the two 1000 cycle start segments and makes contact with the number one segment of the commutator. If a potential has been placed on this segment by the martix 51 as selectively conditioned by the depressed key that started the transmission signal cycle, the #1 segment will be hot (potential could be DC. or high frequency A.C.). In the case of letter E, for example, the receiver circuit to the print hammer magnet 69 is pulsed as the wiper contacts the #1 segment. Such a pulse will occur in a closed circuit from the diode matrix 51 to the #1 segment of the commutator 52, thence through the wiper arm 64 to the wiper disc 66, through the brush contact 67 over communication lines, or the radio network, to the receiver 32 thence through line 184 to amplifier 190 and finally through now closed switch 96 to the print hammer magnet 69. The print magnet armature 104 (see FIGURE 3) is instantly drawn against the force of a bias spring until its pole end is floating in an air gap between the core ends and of the print hammer electro-magnet 69. Upon energization of the electro-magnet, the print hammer head 112 will strike the inked ribbon 114 and record paper 40 against a drum vane 116 with a sharp impact.

Thus, as a result of a completed circuit for a current pulse through the #1 commutator segment, the print hammer armature 104 swings on its pivot toward the print hammer magnet 69, and the thin print hammer head 112, attached to the armature 104, is moved toward the vaned drum S6. The head 112 first strikes the inked ribbon 114 and presses it against the paper 40 and the paper 40, in turn, is pressed against a vane 116 (see FIGURES 3 and 8) of the vaned drum 86 with a resultant printing of a small dot on the paper 70. Each consecutive print operation segment of the commutator 52 is progressively contacted by the wiper arm 64 during its rotation cycle and, if potential has been supplied to that segment by the key selected circuits in the matrix, the completed circuit sends a pulse to the print hammer magnet 69 during the respective time increment within a cycle, and the aforedescribed printing operation is repeated. In such maner, a completed character, as shown in FIGURE 10, is progressively formed. Complete character forming by specific timing of the printing of dots is more fully described in aforenoted application Ser. No. 278,241.

The vaned drum 86 desirably has a small periphery around which four equally spaced apart groups of five equally spaced apart vanes 116 has been secured. Between each group of five vanes 116 there is a blank space 120 which is twice the distance between vanes in a group. Space 120 is provided to accomplish the slight spacing between immediately successive letters, and to provide a non-printing portion of a signal cycle permitting special signals representing carriage return, and stopping and starting functions of the receiver 32. One group of five vanes is used in conjunction with the printing of one symbol or character, and since the exemplary mechanism is arranged to provide a physical space between each symbol equal to one of the five vertical rows of blocks in a character signal, the spacing between groups of vanes is double the spacing between vanes within a group.

As has been previously described, during a receiver print cycle the vaned drum 86 rotates and the hammer carriage screw 92 also rotates through gears 83 and 90. Due to rotation of the carriage screw 92, the print hammer carriage 122 will undergo a gradual movement to the right throughout a printing cycle and while the dots are being progressively printed in the selected squares of the vertical rows to form the character represented by the signal which initiated the print cycle.

Referring to FIGURE 10, the first row 124 of the letter B is printed by cooperation between the print hammer head 112 and the first vane of a group of five vanes 116. Through proper synchronization, the first vane arrives at the proper position near the top of the thin print hammer head 112 at the precise instant that the print hammer magnet 69 is pulsed for the first printed dot at the top of the first row. Any dot required in the various squares of the first row 124 for any symbol or character will be printed on the first vane 11-6 of a group of five vanes, printing occurring from the top down as the vane moves down past the hammer. In the exemplary letter E, all seven dots in the first row are printed by cooperation between the hammer and the first vane of a group of five vanes, forming a straight line, as a result of seven successive pulses derived through transmitter segments It is here noted that when adjacent segments of the transmitter commutator 52 are consecutively energized, the print hammer head 112 remains pressed against the inked ribbon 114 and the rotating vane 116, as it moves down relative to the hammer head, will tend to draw a line on the paper instead of printing a row of dots.

After the wiper 64 has moved off of segment #35 of the commutator 52, it contacts a blank segment #36 and concurrently the receiver stop lever 72 (see FIGURE 7) is mechanically cammed CCW to its stop position, i.e., toward the receiver start-stop magnet 37, by a lug 138 on the carriage screw. shaft which engages a spring leaf arm 140 on the upper stop lever lug 77. The CCW movement of stop lever 72 opens the contacts 102 of receiver magnet switch 96 and prevents any further print hammer D operation during the final rotation of the recorder cycle period. This camming operation of stop lever 72 also causes contacts 94 of the receiver start-stop switch 95 to close and, since there is no longer a 1000 cycle tone signal on the signal line 1 86 and relay 70 has been deenergized, its contacts 180 are closed, enabling the now closed contacts 94 to complete the holding circuit through the coil of the receiver start-stop magnet 37 which holds the armature stop lever 72 in stop position even though the cam lug 138 rotates on past the leaf arm 140, as shown in FIGURE 8 before the stop arm 76 engages the blocking lug 75 to stop the recorder cycle.

Due to the mechanical camming action and re-energizing of the holding circuit just after reception of the 36 segment pulse signal, the start-stop magnet will now be holding the start-stop switch 95 closed. As the commutator wiper arm 64 continues through its cycle, it will next contact segments #36, 37 and 38 (the carriage return-line feed segments) and if current pulses are present on those segments, a circuit through a carriage return-line feed switch 142 on the receiver will be pulsed. The CRLF switch is shown in FIGURES 6, 7, and 8, and in the condition shown in FIGURE 7, has been closed by a lug 232 of a four lobe cam 230 fixed on the function shaft 87. In FIGURE 9, segments #36, 37 and 33 will be hot if a carriage return function is called for from the keyboard transmitter 30. Also, if it is desired that the carriage return-line feed operation be performed automatically, a. special switch 144 seen in FIGURE 1 and circuit fully described in application Ser. No. 278,241 enables the conjoint CR-LF functions to be automatically placed into operation.

Although the fields of use of the telegraphic progressive printing system itself extend beyond the low frequency communication channels, the present invention enables it to be very coveniently used with voice frequency com- .munication channels in existence, without disruption to the voice communication circuit. For example, police cars and fleet operators vehicles could be equipped with receiver units and if the police patrol or vehicle driver left his vehicle he could leave his radio communication channel open with the receiver turned on. Voice communication on the channel would have no effect on starting the receiver cycles yet, if it were desired to leave a written (or recorded) message for the absent driver, a transmitter could transmit the message symbols over the voice channel with the appropriate unique, e.g., 10*00 cycle pulses to start each receiver operation cycle. Conceivably voice communication could even occur during operation and most, if not all of the message symbols would be sufficiently transcribed to provide a legible message.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to the embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. Apparatus for receiving and recording data communication message units in block grid timed sequential pulse combinations transmitted over communication channels comprising:

(a) a recorder with means to receive and record a message represented by such pulse combinations having powered means operative through a timed cycle for translating received block grid timed sequential pulse combination to formed symbols and/or machine functions, and cycling control means adapted to engage and physically start and stop an operative timed cycle of said powered means;

(1) said cycling control means comprising an electro-mechanical device adapted, when electrically energized, to engage and stop said cycling powered means at the termination of a complete cycle, a holding circuit for said electromechanical device responsive to and completed by cycling operation of said powered means for energizing said electro-mechanical device prior to completion of an operative cycle by said powered means; said holding circuit including an operable device which will break the holding circuit only during a period when said operable device is rendered operative; and

(b) means to actuate said cycling control means for starting each message unit cycle of recorder operation comprising a device to detect tone pulses re ceived via the communication channel and having a predetermined unique frequency different from the intra-signal pulse frequency, and means connected to said tone detecting device disposed in control relationship with said operable device and responsive to detection by said detecting means of a plural number of detected successive pulses of the predetermined unique frequency to momentarily render said operable device operative to momentarily break said holding circuit and thereby trigger an operative cycle of said recorder device.

2. Apparatus for receiving and recording data communication message units as defined in claim 1 including means for locally energizing said cycling control means holding circuit and providing electrical isolation of said cycling control means holding circuit from the communication channels.

3. Apparatus for receiving and recording data communication message units as defined in claim 2, wherein said recorder includes a switching device operable to conditions enabling connection and disconnection of said meas to receive timed sequential pulse combinations from the communication channel; and said cycling control means is connected to and operates said switching device to its connection condition only during a period within a cycle of recorder operation.

4. A telescripter receiver for receiving data information, including symbol signals, on communication circuits including voice transmission, each signal comprising a multiplicity of selectively spaced sequential pulse units and including initiating start pulse units each of which has a unique frequency above the normal voice frequency and above the intra-signal pulse unit frequency and a multiplicity of intermediate pulse units equal in number to a predetermined number of blocks in a block grid arrangement of a symbol rectangle, each specific symbol to be transmitted comprising a predetermined order of distinct electrical value pulse units for specific grid blocks in the symbol rectangle which, when visually reproduced in a symbol rectangle space on a record medium, will depict the specific symbol; said receiver comprising:

means adapted to be connected to a communication channel for receiving said signals;

means including a frequency detector rendered operable through a cycle in response to receipt of a predetermined number of initiating start pulses of said unique frequency in a received signal to thereafter respond to other pulse units in said received signal, representing a symbol, to progressively printportions of said symbol in selected blocks of a grid block arrangement corresponding to the specific symbol representative pusle units within a signal, until the symbol is reproduced on a record medium.

5. Apparatus for receiving and recording data communication symbol units in pulse combination-s over voice communication channels comprising: printer means having a cycling control means rendered operable to permit starting and stopping of a cyclic operation of said printer means corresponding to each received symbol unit; means operative on said cycling control means for starting each cycle of operation of the printer means comprising: means adapted to be connected to said communication channel to detect received pulses having a predetermined fre quency located above the normal voice frequency range, and means connected between said detecting means and said cycling control means and responsive to a plurality of successive detected pulses of the predetermined frequency to trigger said cycling control means to start a cycle of recording operation; and said cycling control means includes a cycle start-stop device enabling automatic termination of the receiving operation of said printing means upon completion of a cycle of operation and comprises a power operated mechanically rotatable stop member, an electromagnetic start-stop device having a spring biased armature, shiftable, upon energization of the electromagnetic device, to blocking disposition in the path of rotation of said stop member and shiftable under its spring bias in a direction to remove it from blocking disposition, and means including an electrical circuit connecting to said electromagnetic device rendered operable at the end of a recorder cycle of operation to move said armature to a stop position and to energize said electromagnetic device to maintain said armature in stop position, and said electrical circuit includes a normally closed switch means operable to open condition for momentarily de-energizing said electromagnetic device and a part of said means responsive to detecting said plural number of successive pulses of predetermined frequency.

6. Apparatus as defined in claim 5, wherein said means responsive to detecting of a plural number of successive pulses of predetermined frequency is a relay with a built in time delay before actuation; and said detecting means is a frequency detecting tank circuit in an electrical power circuit connected to apply current to energize said time delay relay only when impressed with a potential of said predetermined frequency from the communication channel.

7. Apparatus for receiving and recording data communication symbol units in pulse combinations over voice communication channels comprising: printer means having a cycling control means rendered operable to permit starting and stopping of a cyclic operation of said printer means corresponding to each received symbol unit; means operative on said cycling control means for starting each cycle of operation of the printer means comprising: a detector circuit adapted to be connected to said communication channel to detect received pulses having a predetermined frequency located above the intersignal pulse frequency, and switching means connected between said detecting circuit and said cycling control means and responsive to a detected pulse of the predetermined frequency to trigger said cycling control means to start a cycle of recording operation, said cycling control means including a cycle start-stop device enabling automatic termination of the recording operation of said printing means upon completion of a cycle of operation, and comprising a local electrical circuit electrically isolated from the communication channel and an electro-magnetic startstop device connected in said local circuit; said switching means being connected to electrically control said local circuit and operable solely through said detector circuit.

8. Apparatus as defined in claim 7, wherein said switching means comprises a solid state switch device and a relay controlled through said solid state device, and said detector circuit is a fraquency detecting tank circuit in control connection with said solid state device to apply current to energize said relay only when impressed with a potential of said predetermined frequency from the communication channel.

9. A receiving printing unit for use in a start-stop telecommunication system, adapted to receive selected electrical signals from a transmitting unit, each selected signal having a multiplicity of intra-signal symbol pulse units effective as point printing signal bits and at least one initial pulse unit with a frequency unique from the frequency of intra-signal symbol pulse units, to progressively print a symbol representative of the transmitted selected signal during an operative printing cycle of the receiving print-ing unit, said receiving printing unit comprising: a start device including a detector circuit and switching circuitry controlled thereby responding to the unique frequency pulse of each selected signal for starting a cycle of operation of the receiving printing unit during which the selected symbol is printed; apparatus separate from said detector circuit and including electromechanical printing mechanism, enabled only by start of the printing unit cycle to receive the intra-signal pulse units of the received selected signal; and means including the switching circuitry controlled by said detector circuit and a mechanically cycling portion of said receiving printing unit for terminating each printing cycle when printing of the symbol represented by each seelcted signal is completed and for replacing cycling initiating control of said receiving printing unit in said detector circuit.

10. Apparatus for receiving and recording data communication symbol units in block grid timed sequential pulse combination signals each of which includes at least one initial pulse unit at a frequency unique from the frequency of the following intra-signal symbol pulse units transmitted over communication channels comprising: a recorder with means to receive and record symbols represented by such symbol pulse unit combinations including an intra-signal pulse responsive printing circuit and powered means operative through a timed cycle for translating received block grid timed sequential pulse combinations signals to formed symbols and/or machine functions, and cycling control means adapted to engage and physically start and stop an operative timed cycle of said powered means; said cycling control means comprising an electro-mechanical device adapted to star-t and stop said cycling powered means to enable its operation through a complete cycle; a control circuit for actuating said electro-mechanical device to enable an operative cycle by said powered means including a switching device which enables making and breaking of said control circuit; and means to actuate said cycling control means for starting each symbol unit cycle of recorder operation comprising a detector circuit separate from said printing circuit to detect 'at least the pulse of unique frequency diiferent from the frequency of the intra-signal pulse units received via the communication channel, and means connected between said unique frequency detecting circuit in control relationship with said switching device and responsive to detection by said detecting means of a detected pulse of the predetermined unique frequency to render said switching device operative to momentarily enable operation of said control circuit to thereby trigger an operative cycle of said recorder device.

11. A receiver as defined in claim 10, said detector circuit being constructed to be responsive to received pulses in a frequency range higher than possible intrasignal pulse frequencies and normal voice frequencies.

12. A progressive printing receiving recording unit for use with .a telegraph system wherein each symbol signal is represented by a single electrical signal consisting of initial pulse units of unique frequency and a multiplicity of intra-signal symbol pulse units, said symbol pulse units being efiective as point printing signal bits to progressively scribe a printed symbol representative of the transmitted selective signal, comprising: means for receiving said signal, including circuit means for detecting said unique pulse units; means including a circuit separate from said detecting circuit for receiving the symbol pulse units and recording by progressive transcription printing, the symbol represented by said signal and also including a control circuit and a switching device actuated solely by said detecting means for causing the initial pulse units of said sybol signal to start the recording means; and comprising portions of said receiving means and portions of said recording means for stopping said recording means after each symbol recordation and prohibiting star-ting by said detecting means until said recorder is conditioned for the beginning of recordation of the subsequent received symbol representing signal.

References Cited UNITED STATES PATENTS 2,658,106 11/1953 Hell 178-30 2,823,261 2/1958 Zipf 179-3 2,865,992 12/1958 Reek et a1. 178-53.l 2,365,458 12/1944- Deloraine.

THOMAS A. ROBINSON, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,387,087 June 4, 1968 Edward E. Kleinschmidt It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 74, "system" should read systems Column 8, line 71, "has" should read have Column 12, line 44, "fraquency" should read frequency line 71, "seelcted" should read selected Column 14, line 18, "sybol" should read symbol Column 11, line 19, cancel "telescripter".

Signed and sealed this 13th day of January 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents 

